How To Remove A Ceiling Electrical Box
Dear Mr. Electrician: Should I replace former ceiling pancake box for a new ceiling light fixture installation? Afterwards removing the existing lite fixture canopy cover, I plant that there isn't a standard ceiling electric junction box. Instead, there is a black round disc (about 3 inches in diameter) which has a one inch long screw type rod sticking out of it. The wires are around it. This is not uniform with the new light fixture that I want to install. What exercise I practice?
Answer: You demand to replace quondam ceiling pancake box. Annotation: Some text links below go to applicable products on Amazon. Equally an Amazon Associate I earn from qualifying purchases.
I doubtable that the circular disc is really an old black enameled metal pancake box. Information technology's approximately the diameter and thickness of a hockey puck and made out of metal.
Sometimes an sometime gas pipe protrudes from the middle of this pancake box instead of a fixture stud. A setscrew tightens the box to the gas pipe.
One-time CEILING PANCAKE BOX
That was how old houses that originally had gas lighting converted over to electrical lighting. The pancake box was mounted on to an existing disconnected gas pipe. The cables were attached to the pancake box and splices were made. An additional fitting such as a 3/8″ x one/8″ hickey was threaded onto the gas pipe to support the light fixture which was fabricated for this blazon of installation.
The canopy of the old style ceiling light fixture acted as the junction box for the spliced wires. When calculating box fill for the maximum number of wires allowed, you can include the cubic inch capacity of the light fixture awning co-ordinate to commodity 314.16(A) in the National Electrical Lawmaking.
On very rare occasions I accept found that the gas pipes were however connected to the master gas line after I removed an former light fixture or the cap on the gas pipe, and so proceed with caution.
I got a call to install a new light fixture. The above photo was what I constitute when I arrived. The fan bracket was screwed to the ceiling independently using long sheet metal screws driven into the ceiling wood joist. The remains of the cut old ceiling fan wires protruded downwards.
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Other types of sometime pancake boxes were mounted direct onto ceiling joists using woods screws. Instead of an opening for a gas pipe, they would have their ain fixture stud for attaching a light fixture to. The fixture stud had the aforementioned size thread as a gas pipe of the same diameter.
Around the pancake box are 4 holes, each with a setscrew or clench which engages the cable, preventing it from being pulled out, and provides electrical continuity for the equipment ground for the armored cable.
The wiring is near likely armored cable (BX). However ungrounded not-metallic cablevision (The Blazon Before Romex), or knob and tube type wiring is possible as well.
Beware if the gas piping has a cap on it. Unremarkably the caps are removed when the gas line is taken out of service. However, until you tin verify that the gas line is dead you should not remove the cap.
In a situation where the original wiring insulation has degraded, the best matter would exist to install new wiring. Notwithstanding that non only could be expensive, but damaging likewise. Walls and ceilings may need to be cut open up to re-route or remove old dried and brittle cables and install new wiring.
Equally yous tin can meet above most of the old insulation broke off every bit I moved the wires. Notice that I identified the conductors with colored electrical tape. This was a normal wiring set upwards for a ceiling lite controlled by a wall switch. Here the power entered into the pancake and a 2 wire cable was installed down to the switch. See my mail service on light switch wiring diagrams for more information.
REPLACEMENT OF OLD STYLE PANCAKE BOX
Turn off the ability. You volition need to remove the old pancake junction box. Do information technology carefully so as to not damage the existing wiring. Oft, wiring from that era of home construction now has dry, breakable insulation on information technology. Any disturbance to the wires could crusade the insulation to break off.
Make sure that you place each conductor in the box before you lot have autonomously the splices. The color coding is about gone on these wires. The wires are likely to exist soldered and taped. The insulation on the wires volition pause off as you separate the conductors. Get a roll of white and a scroll of black electric record. You may also need rolls of cerise and blue electric record.
Information technology doesn't show it above, but I was able to strip near 2″ of steel armor off of each cable using BX cutting pliers. I held the cable with Channellock pliers and slowly nipped away at the steel armor using the BX cutters. That gave me enough room to find some skillful insulation to work back from with new electric record.
On some jobs the gas pipe will be a hindrance to installing a new modern round or octagonal ceiling electrical box. Also it is quite probable that there is a piece of wood supporting the gas pipage or the pipe may exist fastened to the side of a ceiling joist.
Sometimes a pipe wrench can be put on the gas pipage to unscrew it from the elbow. An internal pipe wrench might be needed. Other options are cut information technology out with a multi-office aquiver tool or a reciprocating saw, or relocating the ceiling box. Relocating may non be an option due to the lengths of the existing wires.
One time all obstacles have been removed and the existing cables have been identified and taped, a new electric box can be installed. A new pancake box tin exist used or sometimes an one-time piece of work ceiling fan caryatid and box can be fitted through the existing hole. A side mount type fan box is as well bachelor if the joist is right there. Try to get the deeper circular electrical boxes as they have more room for wires.
If you are planning to install a ceiling fan, and so yous must install an electric box rated for ceiling fans. Ceiling fan boxes are available in pancake depth.
A duplex BX connector was used to adhere the cables above to the pancake box. I had to clean upwardly the opening in the ceiling with my multi-tool due to pieces of woods lath and plaster embedded with the old pancake.
Use the proper cable connectors and anti-brusque bushings for the cables and bring them into the back of the box. Trim the sharp edge of the BX cable using BX cutters or diagonal pliers. Then insert the anti-short bushing inside of the armor to protect the wire from beingness cut past the metal armor.
In this case it may be best to put the cable connectors on the ends of the cables with the locknuts removed. Record the ends of the wires together. As you push the box into the ceiling, pull the cables through each connector.
Tighten the locknuts by hitting them with a screwdriver driven by a hammer after the box is secured to the ceiling or subclass or use Channellock pliers or a locknut wrench. The BX cable metal armor is the grounding conductor, then it needs to be a tight connectedness.
A grounding pigtail was attached to the pancake box below using a ten/32 green grounding screw. The box is grounded from the BX cablevision's metallic armor and the pigtail tin can be used to ground the new light fixture.
The box above is gear up for a standard light fixture installation. Number x x 1.5″ sheet metal screws were used to secured the pancake box to the ceiling joist. The box is grounded through the correct employ of the cable connector and the BX armor. A grounding pigtail was added using number 14 wire. The wire with crimson is the switch leg (LOAD) which gets connected to the black wire on the light fixture.
The white wire with light-green (The LINE to the switch) was partially covered in black tape before getting connected to the black hot wire with greenish (LINE). When a white wire is used for something other than a neutral, information technology must exist re-identified. I employ colored electric tape. Some other electricians use a permanent marker pen to change the wire color.
The other white wire (Neutral), gets connected directly to the white wire on the light fixture. The green tape was used for my own purposes in identifying the wires as I worked on this repair.
The green tape was removed before I made the last connections to the calorie-free fixture. Green is only to be used for identifying a grounding wire.
In the above box you lot can see that two knockouts have not been punched out.
Old CEILING PANCAKE BOXES FROM VISITORS
A visitor to my blog sent me the above photo of a pancake box with live electric wires nevertheless in use. The house is from 1930. His dilemma was how to remove the box. There are no spiral holes in the dorsum of the box, but there is a metallic bar that passes through (See yellow circumvolve).
I surmised that the metallic bar is a support bracket that is either attached straight betwixt two ceiling joists, or screwed to wood board. The box is held firmly onto the bracket by the middle screw. If that is the case, then some plaster would need to be removed in order to remove the bracket.
I suggested possibly cutting the bracket with an oscillating multi-tool so that an old work fan box and brace could be installed. Nonetheless, with a house that quondam it is quite possible that the plaster would be damaged during the cutting procedure.
The insulation on the wires is in good condition, simply I recommended taping each wire with the appropriately colored electric tape to proceed the insulation intact. White tape on the iii neutral conductors. Blackness tape on the iv hot wires. Red record on the switch leg.
The cable in the upper left section of the pancake box is the 1 that goes down to the wall switch. The white wire from this cable is continued to the 3 blackness hot conductors. The blackness wire which brings the power back from the switch is by itself. These wires should also be re-identified at the switch with red and black electrical tape.
A white wire can be used as a hot conductor, simply it must have its color inverse to something other than white, grayness, or green. Electrical tape or a permanent ink mark are two common methods for changing the colour of wires. Unfortunately the re-identification of the white wire does not always occur equally evidenced in the higher up moving-picture show.
Another visitor to MrElectrician.Goggle box sent me the photo below of what he found when he lowered the awning cover on an existing light fixture in his 1906 home.
The house from the above photo was originally piped for gas lighting. At some signal in its history electric wiring was installed. Normally in a gas to electricity retrofit, a pancake electrical box would slide over the gas pipe and a gear up screw would lock it in place. The new BX wiring would have terminated in the pancake box.
The ceiling light fixtures from that era mounted differently than the lite fixtures of today in society to arrange the gas pipes. I surmise that at some bespeak someone wanted a new mod light fixture and found it would not mountain onto the onetime pancake box or gas pipe. So the pancake box was removed and the bracket that unremarkably mounts on an electric box was screwed directly to the ceiling.
This is the wrong manner. The wires are not protected in an electrical box and the grounding continuity through the BX armor is lost.
I suggested that the homeowner install an adjustable ceiling fan caryatid and box that would retrofit inside of the existing hole in the ceiling. However the problem is that old gas piping protruding from the ceiling. It appears that someone already tried to remove information technology without much success.
I have been in this situation myself and tin can attest that it tin can exist almost incommunicable to unscrew the pipe from its base. In those instances I had to use a reciprocating saw to cutting it out. The saw works well with the right blade in cut out the pipe, but it can besides practise some damage to the ceiling in the process.
Some other visitor to MrElectrician.TV sent me the beneath photo with a question: "I am replacing an old chandelier in the living room of my pre-1915 flat. Later on removing the old fixture I discovered that it was hanging from a hickey fastened to a threaded pipage in the center of the non-load-begetting pancake box. The ceilings are concrete.
My question is whether it is safety to hang the new fixture from the eye pipe using a hickey, or whether it would be necessary to bring in an electrician to supercede the box with a newer one designed to support the weight of the new fixture using a strap?
The former fixture weighed 26 lbs, and the new 1 will weigh 55 lbs."
My response: "I don't remember I tin give you a definite answer one fashion of some other, just I can share my thoughts.
Given that there are electrical conduits with wires in that electrical box, I don't think that there was gas lighting there originally. Normally a retrofitted gas pipe would have cables that were fished over to the gas pipe and a box with a set spiral or locknut would be installed over the pipe.
That pipe that is protruding is either part of the electric box or was added as an accessory during the original installation for the purpose of light fixture hanging.
Since the unabridged conduit and box assembly is embedded in concrete, a replacement of the box will be challenging and would require repair to the ceiling.
I would attempt pulling on the pipe using your ain body weight to become a feel of the strength of the pipe. My guess is that it is pretty solid.
Depending on the blazon of bracket that is furnished with the new calorie-free fixture, yous may exist able to provide additional support by screwing the bracket directly to the concrete using 1/4″ plastic anchors with #12 sheet metal screws, in addition to using the pipe as a back up. I am assuming that the physical is in good solid condition.
If the hickey is too large for the new low-cal fixture canopy yous can besides use locknuts on the pipage, though they tin be difficult to find locally."
"In 1915 the standard mountain for a ceiling low-cal fixture was with a pipage and hickey. No screw hole tabs on electrical ceiling boxes were available then. I don't know exactly when the change occurred, but am guessing before WW2 based on other old wiring that I have seen.
Also back then the ceiling boxes were shallow and did not have allowances for the number of wires because the light fixture canopy had a lot of room. The electrical lawmaking nevertheless allows the cubic inch capacity of the canopy to be included when calculating box fill.
The original wires that were installed in the conduit were cloth covered. Having the conduits in identify fabricated it very like shooting fish in a barrel to replace the onetime wires with the plastic insulated ones that y'all now have when the apartment was renovated.
Many years ago I had to replace fabric covered wires in conduit installed around the same time equally yours. When I pulled the old wires out the insulation came off inside the conduit. I had to repeatedly button a fish tape in and pull out pieces of insulation before I could pull new wires in.
The conduits are virtually likely helping to support the box given that you tin push up on the center pipe, only are not able to pull down.
You could attempt drilling and borer 2 holes in the back of the box and apply longer screws to attach the light fixture. Withal with the weight of the new low-cal fixture I would use bigger screws so the standard 8/32.
Under normal conditions I would replace a standard ceiling box with a fan rated ceiling box in order to back up a lite fixture that weighed over 50 pounds."
On the center stud of the in a higher place pancake box is a contumely screw-on cap. I forget how it was used, but I think it had to do with hanging calorie-free fixtures.
A grounding pigtail wire is easily attached to the side of a grounded metal electrical box using a footing clip. That grounding pigtail tin be used to basis a light fixture or wiring device. The to a higher place pancake box would need to accept BX cable connected to information technology in gild to be grounded. This box is not fabricated for Romex.
For more information on switch wiring, see my postal service with low-cal switch wiring diagrams here.
The National Electric Code accepts the use of pancake ceiling boxes fifty-fifty though they do not take a lot of cubic inch capacity. They are permitted because the lawmaking allows the cubic inch chapters of the calorie-free fixture canopy to exist included in the total calculation of box fill up. See article 314.16(A).
Generally speaking, for each #14 wire two cubic inches is required. For #12 wire information technology is 2.25 cubic inches. Each internal wire clamp counts every bit one wire. Read article 314.sixteen for all of the details.
My blog mail on repairing a loose ceiling electrical box may be helpful.
As well my post on installing a ceiling fan electrical box is expert to read.
Source: https://mrelectrician.tv/replace-old-ceiling-pancake-box/
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